How can i draw one red pixel in the shader instead of the triangle (in java)?

Question

I'm new to programming in java with shaders
https://code.sololearn.com/cdOVAkoP34LA/?ref=app

Answer 1

What I see is:
-change the vertex shader code to a minimal shader since we only need a single point.
-Modify the onDrawFrame method to draw a single point at the center.